docs: def overlay_pdfs(top_pdf, bottom_pdf, destination):
      """
      Overlay PDF objects to files
      :param top_pdf: PDF object to be placed on top
      :param bottom_pdf: PDF file to be placed underneath
      :param destination: Desintation path
      """
      drawing = PdfFileReader(top_pdf)  # Create new PDF object
      template = PdfFileReader(bottom_pdf)  # read your existing PDF
  
      # add the "watermark" (which is the new pdf) on the existing page
      page = template.getPage(0)
      page.mergePage(drawing.getPage(0))
      output = PdfFileWriter()  # Create new PDF file
      output.addPage(page)
  
      # finally, write "output" to a real file
      with open(destination, "wb") as outputStream:
          output.write(outputStream)